/// <summary>
/// Can be used in the call to Fill() as the default labeling function.
/// This function merely colors the pixel in the color specified under labelCookie
/// which should be a Color object.
/// </summary>
public static void DefaultLabeling(CVImage outputImage, Point pt, object labelCookie)
{
if (!outputImage.Contains(pt)) return;
if (outputImage[pt].GrayLevel != 0) return;
Color c = (Color)labelCookie;
outputImage[pt] = new CVRgbPixel(c);
}
private void ProcessBackgroundSubtraction()
{
CVImage frame = videoPlayer.LastFrame;
// access last frame from video player.
for (int row = 0; row < frame.Height; ++row)
{
for (int col = 0; col < frame.Width; ++col)
{
CVRgbPixel pixel = frame[row, col];
// get black and white value for this pixel.
int bwValue = pixel.BwValue;
// accumulate the new value to the moving average.
double val = (double)bwValue / 255.0;
if (bgAccum[row, col] == -1)
{
bgAccum[row, col] = val;
}
else
{
bgAccum[row, col] = alpha * val + (1 - alpha) * bgAccum[row, col];
}
// calculate the diff between the frame and the average up until now.
double delta = val - bgAccum[row, col];
byte currentBgValue = bgFrame[row, col].BwValue;
if (currentBgValue > 0)
{
currentBgValue -= STEP_SIZE;
}
// if delta is smaller than the threshold, eliminate the background.
if (delta < threshold)
{
// set the color of the background frame to black.
//bgFrame[row, col] = new CVRgbPixel(0, 0, 0);
}
else
{
currentBgValue = 255;
}
bgFrame[row, col] = new CVRgbPixel(currentBgValue, currentBgValue, currentBgValue);
}
}
// display the updated frame on the window.
bs.Image = bgFrame.ToBitmap();
}
/// <summary>
/// Creates a new image that will be used as a mask for the histogram calculation.
/// All forground points will be colored blue and all background points will be colored red.
/// </summary>
public static CVImage PrepareMask(CVImage image, Point[] forgroundPoints, Point[] backgroundPoints, bool includeNeautral, int floodFillThreshold)
{
CVImage outputImage = image.Clone();
outputImage.Zero();
FloodFillParams ffp = new FloodFillParams();
ffp.Frame = image;
ffp.Threshold = floodFillThreshold;
// fill all forground points in FG_COLOR
foreach (Point pt in forgroundPoints)
{
RegionGrowing.Fill(pt, outputImage, new RegionGrowingCriteria(FloodFill), ffp, new LabelingFunc(RegionGrowing.DefaultLabeling), FG_COLOR);
}
// fill all background points in BG_COLOR
foreach (Point pt in backgroundPoints)
{
RegionGrowing.Fill(pt, outputImage, new RegionGrowingCriteria(FloodFill), ffp, new LabelingFunc(RegionGrowing.DefaultLabeling), TEMP_BG_COLOR);
}
// now colorize to actual colors.
for (int row = 0; row < outputImage.Height; ++row)
{
for (int col = 0; col < outputImage.Width; ++col)
{
int argb = outputImage[row, col].ToColor().ToArgb();
if (includeNeautral)
{
if (argb == Color.Black.ToArgb())
{
outputImage[row, col] = new CVRgbPixel(NEAUTRAL_COLOR);
}
}
if (argb == TEMP_BG_COLOR.ToArgb())
{
outputImage[row, col] = new CVRgbPixel(BG_COLOR);
}
}
}
// return as a grayscale image.
CVImage grayscale = outputImage.ToGrayscale();
outputImage.Release();
return(grayscale);
}
/// <summary>
/// Can be used in the call to Fill() as the default labeling function.
/// This function merely colors the pixel in the color specified under labelCookie
/// which should be a Color object.
/// </summary>
public static void DefaultLabeling(CVImage outputImage, Point pt, object labelCookie)
{
if (!outputImage.Contains(pt))
{
return;
}
if (outputImage[pt].GrayLevel != 0)
{
return;
}
Color c = (Color)labelCookie;
outputImage[pt] = new CVRgbPixel(c);
}
/// <summary>
/// Called by the video player to handle the next video frame.
/// </summary>
private void videoPlayer1_NextFrame(OpenCVDotNet.UI.VideoPlayer sender, OpenCVDotNet.UI.NextFrameEventArgs args)
{
// args.Frame contains the frame to be handled.
CVImage frame = args.Frame;
// go over all the pixels (rows, cols)
for (int y = 0; y < frame.Height; ++y)
{
for (int x = 0; x < frame.Width; ++x)
{
CVRgbPixel pixel = frame[y, x];
// invert RGB colors.
frame[y, x] = new CVRgbPixel(
(byte)(255 - pixel.R),
(byte)(255 - pixel.G),
(byte)(255 - pixel.B));
}
}
// assign resulting frame to picture box as a bitmap.
pictureBox1.Image = frame.ToBitmap();
writer.WriteFrame(frame);
}
/// <summary>
/// This function applies the mask to image in the following way:
/// - All pixels in 'mask' that are blue are copied to the output image in maximum intensity.
/// - All pixels in 'mask' that are black are copied to the output image in half intensity.
/// - All pixels in 'mask' that are red are not copied at all to output image.
/// </summary>
public static CVImage ApplyMask(CVImage image, CVImage mask)
{
CVImage outputImage = image.Clone();
outputImage.Zero();
for (int row = 0; row < image.Height; ++row)
{
for (int col = 0; col < image.Width; ++col)
{
// copy everything that's not background.
if (mask[row, col].ToColor().ToArgb() != Color.Black.ToArgb())
{
outputImage[row, col] = image[row, col];
}
else
{
outputImage[row, col] = new CVRgbPixel(TEMP_BG_COLOR);
}
}
}
return(outputImage);
}
private void Work()
{
CVImage frame;
try
{
while (true)
{
ReopenCapture();
while ((frame = cap.QueryFrame()) != null)
{
for (int row = 0; row < frame.Height; ++row)
{
for (int col = 0; col < frame.Width; ++col)
{
CVRgbPixel pixel = frame[row, col];
// get black and white value for this pixel.
byte bwValue = pixel.BwValue;
// accumulate the new value to the moving average.
double val = (double)bwValue / 255.0;
avg.Accumulate(row, col, val);
// calculate the diff between the frame and the average up until now.
double delta = val - avg[row, col];
// if delta is smaller than the threshold, eliminate the background.
if (delta < Threshold)
{
// set the color of the background frame to black.
frame[row, col] = backgroundColor;
}
else
{
// if monochrome is checked, set pixel to foreground color.
if (monochrome.Checked)
{
frame[row, col] = foregroundColor;
}
}
}
}
// display the updated frame on the window.
cvPanel.Image = frame.ToBitmap();
if (vw != null)
{
vw.WriteFrame(frame);
}
// delay for 20ms.
Thread.Sleep(20);
frame.Release();
}
}
}
catch (CVException e1)
{
MessageBox.Show(e1.Message);
}
catch (ThreadAbortException)
{
Console.WriteLine("Aborting thread...");
}
finally
{
if (cap != null)
{
cap.Release();
}
if (vw != null)
{
vw.Release();
}
}
}
